The invention relates to a device for switching an electric connection, especially a hinge switch, as described in the disclosure part of claim 1.
A device of this sort is already known from WO 93/24946. On the pin which is actuated from outside the device is arranged a multiple-component cam plate serving as actuating means, on the peripheral surface of which engages a switching device in the form of a switch tappet which switches the electric connection when a certain switching point has been exceeded. All of the three parts of the cam plate are arranged and affixed relative to one another in the direction of rotation of the pin during assembly of the device. By switching the contact surfaces associated with the parts, they define the position and the dimensional extension of a switching notch or groove for the tappet on the peripheral surface of the cam plate.
The multiple-component cam plate used in the known device requires a high outlay for manufacture, and particularly for the assembly of such devices. Adjustment of the switching point following the assembly is not possible, and moreover the device must be completely disassembled for a new setting of the switching point for which several fixing screws must be released, which following the new setting adjustment must be screwed back in again.
DE-AS 10 91 187 discloses a rotary switch with cam disks which in turn are secured removably on the switch pin by means of a fastening screw. The fastening screw used for this purpose can be inserted in a passage passing all the way through the switch pin and can be screwed into a threaded bore of the cam disk. In this case, the position of the cam disk in relation to the switch pin is adjustable neither in radial nor axial direction nor in peripheral direction.
DE-OS 21 45 115 discloses a rocking lever switch having a snap-switch device. The switching means or the tappet is made up of an actuator sheathing and a switching pin which can be screwed together, whereupon the effective length of the tappet and thus of the switching point can be adjusted.
U.S. Pat. No. 403,169 discloses a cam having a different type of mechanical control device. A bushing element which can be connected with a pin can be detachably secured at several discrete positions on the cam. The discrete positions are predetermined invariably by cooperating gearing arranged both on the bushing element and on the cam plate.
The object of the present invention is to provide a device as described in the disclosure part of claim 1 which will guarantee a simple and permanent precision setting and adjustment of the switching point using relatively few constructive elements.
The problem is solved by means of the device claimed in claim 1. Particular different embodiments of the invention are disclosed in the dependent claims.
With the solution of the problem according to claim 1 the switching of the electric connection involves the opening and/or closing of at least one pair of contacts. The pin can be configured either as pivotal only back and forth or else can be configured to rotate, making complete revolutions. The switching means can be mounted on the actuating means and displaced in radial or axial direction on the actuating means in relation to the pin. The simple radial and/or axial displacement of the actuating means to be undertaken simply in relation to the pin guarantees the capacity to perform a permanent and precise adjustment and readjustment of the switching point. For certain types of uses the traditional switching point is arranged at a rotation of the pin of approximately 3 degrees. Preferably the switching means has a longitudinal axis which with the pin forms an angle of 90 degrees. Preferably the longitudinal axis of the switching device and the longitudinal axis of the pin intersect. The actuating means is preferably configured of one single piece. The adjustment means is preferably arranged in threaded, clamped or catch connection with the pin.
The particular type of embodiment disclosed in claim 2 offers the advantage that by simple rotation of the headless screw the position of the actuating means can be modified in relation to the pin and thus the switching point can be adjusted simply and precisely. Therefore, because of its stationary arrangement in relation to the actuating means, the headless screw serves as part of the interlocking gearing of the rotary movement of the pin on the actuating means. Particularly, with this arrangement, additional secure fixing of the actuating means on the pin with regard to its rotary movement can be relinquished. These headless screws are frequently also indicated as setscrews.
The particular embodiment according to claim 3 has the advantage that with headless screw screwed into the pin the actuating means can be displaced by inward thrust or can be simply inserted into the pin for example during the assembly of the device, whereby the headless screw can be inserted into the mounting opening at least partially form-locking. Preferably the headless screw has a threadless, journal-like segment at each of its ends, which can be inserted into the corresponding mounting.
The particular type of embodiment of claim 4 has the advantage that the actuating means is affixed simply and reliably in its axial position on the pin. Insofar as the actuating means can be screwed in axial direction in relation to the pin by means of the adjustment means, the pin retaining ring serves as a stop for the axial displacement of the actuating means and if required can be further supplemented by a flexible element for example in the form of a helical spring applying a return force in axial direction when acting on the actuating means.
The particular embodiment of claim 5 offers the advantage that even reduced switching angles can be permanently and precisely adjusted. By its engagement on the peripheral surface the switching means is displaced in the direction of contact during rotation of the pin and when it passes over the segment. Alternatively to and/or in supplement to the notch or groove found thereon, the peripheral surface can also incorporate one or more cams in its design. Alternatively to the use of a cam plate, a lever having one or more arms can be used, with the lever arrangement cooperating with the switching means.
The particular embodiment of claim 6 offers the advantage that the adjustment means do not come into contact with the switching means and thus that complete revolutions of the pin are possible, because the adjustment means are arranged to be axially displaced relative to the peripheral area and particularly relative to the contacting of the switching means on the peripheral surface of the cam plate.
The particular embodiment of claim 7 provides the advantage that the adjustment range for the actuating means can be predetermined simply by providing the dimensions of the longer edge of the rectangle of simple construction and of ample size. In the area of the actuating means the pin preferably has a smaller diameter than the outside of the device. In the area of the actuating means, the pin can be provided with one or with two diametrically opposite parallel surface areas, of which the spacing corresponds to the length of the shorter edge of the rectangle, whereupon a still more precise guiding of the actuating means in its displacement in radial direction in relation to the pin can be guaranteed.
The particular embodiment according to claim 8 provides the advantage that with such a constructively simple solution a reliable switching is guaranteed preferably by axial displacement of the tappet. A spatial separation of the mechanical and electrical components is thus attained.
The particular embodiment according to claim 9 offers the advantage that an adjustment or readjustment of the switching point is possible even following the assembly of the device or for example within the framework of maintenance and repairs.
The particular embodiment as in claim 10 offers the advantage that this embodiment makes possible a simple mechanical coupling for example to a protective arrangement of a machine tool, which protective arrangement is to be monitored. The device can be fastened for example to a housing of the protective arrangement or to the machine tool itself, whereas the pin is connected with the hinge rod or the hinge bolt of a protective gate or protective cover or hood articulated on the housing, for example by means of a connecting sleeve.